Lecture by Enzo Tagliazucchi: From molecules to consciousness: towards an integrative neuroscience of psychedelics

Suppose someone consumes a typical dose of lysergic acid diethylamide (LSD). The molecules are absorbed by her body and cross the blood-brain barrier, finally interacting with proteins located at the cell membrane (receptors). Depending on the receptor and the type of interaction with the LSD molecule, different intracellular second messengers are recruited, which in turn modify the biophysical properties of the cell and influence its activity. The next two facts we know about are that the contents of her consciousness are deeply modified, and that such modifications are related to changes in brain activity, as measured with tools such as fMRI, EEG and MEG. But what happened in between?

Currently, we have knowledge about the two ends of the process, but how can we connect both ends? In my talk I will move between theory and experiment to propose a way to link scales based on the following assumptions: 1) That it is possible to map the state of the brain (at different scales) into a space with a distance function or metric (i.e. there is a notion of the proximity between two states), 2) That it is possible to map the contents of consciousness into a similar space, and 3) That it is possible to investigate how the distance functions from both spaces relate to each other, e.g. does “being close“ in one space imply “being close“ in the other?